Photovoltaic solar power systems are an increasingly attractive alternative to using legacy power generating technologies due to growing concerns about the sustainability and cost of such legacy technologies. However, limitations of commercially available photovoltaic solar power systems have prevented their widespread acceptance and use.
Conventional photovoltaic solar power systems are typically complicated and expensive to install. They are often weighty and cumbersome, and may require special support structures. For example, when a conventional solar power system is installed on a building's roof, special support structures may be required to support the power system. Additionally, a conventional solar power system may significantly increase a roofs weight and/or wind load when installed on the roof. In some cases, the quantity of modules needed to generate the desired power would exceed the roof's rated structural limits, thereby preventing the installation of the required photovoltaic solar power system.
The installation of such conventional solar power systems is in itself problematic. Conventional solar power systems are typically built from a large number of rigid, heavy photovoltaic modules of relatively low voltage and power, that are frequently difficult to transport and maneuver. The photovoltaic modules must be delivered to an installation site, individually disposed in their proper locations at the installation site, and individually connected with cables, wires, breakers, boxes, combiners, and/or connectors. Furthermore, due to their low voltage and relatively low power output, there is generally a need to wire a large number of photovoltaic modules in series and/or in parallel. Photovoltaic modules need to be wired in series to achieve a desired open circuit output voltage, and photovoltaic modules need to be wired in parallel to achieve a given current rating for the overall system. Typically, for a given circuit, a plurality of modules are connected in series, referred to as a string, to achieve the desired voltage, and in turn, several of these strings are connected in parallel to achieve the desired current for this circuit. Therefore, installation of conventional solar power systems is generally labor intensive, complex, and costly.
Additionally, the multitude of components required in traditional solar power systems (e.g., cables, wires, breakers, boxes, combiners, and connectors) increase the complexity of the system, which may decrease its reliability and/or increase its maintenance requirements. Furthermore, the cost of such multitude of components is often significant, thereby contributing to the relative costliness of traditional solar power systems.
Conventional photovoltaic solar power systems are also frequently difficult to adapt to topographical features of real world installation sites, thereby limiting their adoption. Installation sites often contain obstructions (e.g., a roof may contain vents, skylights, heating, ventilation and air conditioning (HVAC) equipment) which limit a contiguous area available for disposing photovoltaic modules thereon. Further complicating these installations is that by necessity, the PV array must be oriented to accept the sun's rays most directly, while the building's rooftop is not always oriented to easily accommodate this requirement. Accordingly, solar power systems must be built around such obstructions. However, components of conventional solar power systems generally have fixed dimensions, which prevents them from being customized to a particular installation site to work around obstructions. For example, if a roofs surface is broken up by two plumbing vents, conventional solar power system components may not be available in suitable dimensions to be disposed between the plumbing vents.
Furthermore, as described above, a certain quantity of traditional photovoltaic modules of conventional solar power systems must be connected in series to achieve a desired output voltage, thereby limiting flexibility in disposing the components in an installation site. For example, consider a roof broken up by a chimney. In order to work around the chimney while still connecting enough traditional photovoltaic modules in series to achieve a required open circuit output voltage, one or more component photovoltaic modules in a string may be placed away from its fellow, series-connected photovoltaic modules. This requires additional wiring, and may result in sub-optimal coverage over an installation site.